Exhaust fluid filter including hydrocarbon detection witness media

ABSTRACT

An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a National Stage of PCT Application No.PCT/US2014/064853, filed Nov. 10, 2014, which is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to exhaust aftertreatmentsystems for use with internal combustion (IC) engines.

BACKGROUND

During the combustion process in an IC engine (e.g., a diesel-poweredengine), sulfur is concurrently formed with carbon monoxide (CO) andhydrocarbons (HC) as various sulfur oxides (SO_(x)). Typically, 97-99%of the total amount of SO_(x) present in exhaust gas includes sulfurdioxide (SO₂) and 1-3% includes sulfur trioxide (SO₃). Thus, fuels withhigher sulfur content tend to produce higher amounts of SO₃. Forexample, fuel with sulfur content of 1000 ppm may form approximately 1-3ppm SO₃.

Exhaust aftertreatment systems are used to receive and treat exhaust gasgenerated by IC engines. Conventional exhaust gas aftertreatment systemsinclude any of several different components to reduce the levels ofharmful exhaust emissions present in exhaust gas. For example, certainexhaust aftertreatment systems for diesel-powered IC engines include aselective catalytic reduction (SCR) catalyst to convert NO_(x) (NO andNO₂ in some fraction) into harmless nitrogen gas (N₂) and water vapor(H₂O) in the presence of ammonia (NH₃). Generally in such conventionalaftertreatment systems, an exhaust reductant, (e.g., a diesel exhaustfluid such as urea) is injected into the aftertreatment system toprovide a source of ammonia, and mixed with the exhaust gas to partiallyreduce the SOx and/or the NOx gases. The reduction byproducts of theexhaust gas are then fluidically communicated to the catalyst includedin the SCR aftertreatment system to decompose substantially all of theSOx and NOx gases into relatively harmless byproducts which are expelledout of such conventional SCR aftertreatment systems.

A major cause of breakdown and failure of conventional SCRaftertreatment systems includes contamination of the exhaust reductantwith hydrocarbons. For example, the exhaust reductant can becontaminated with diesel fuel, injector cleaner (e.g., toluene), orengine oil. The hydrocarbons contaminating the exhaust reductant cansuper heat the selective reduction catalyst, dissolve ethylene propylenediene monomer (EPDM) seals included in an exhaust reductant tank orpump, dissolves linings from the exhaust reductant tank and lines, andcan also swell a diaphragm of the exhaust reductant pump. Hydrocarboncontamination accounts for about 37% to about 50% of all failures of SCRaftertreatment systems. This results in a significant number of warrantyclaims from customers, as it is not always possible to determine if thefailure of the SCR aftertreatment system was due to hydrocarboncontamination, which can be attributed to customer oversight.

SUMMARY

Embodiments described herein relate generally to exhaust aftertreatmentsystems for use with IC engines, and in particular to exhaustaftertreatment systems that include an exhaust reductant filter with ahydrocarbon witness detection media (also referred to herein as“hydrocarbon detection device”). In some embodiments, an aftertreatmentsystem includes an exhaust reductant tank configured to store an exhaustreductant. A filter is fluidically coupled to the exhaust reductanttank. The aftertreatment system includes a hydrocarbon detection deviceconfigured to indicate the presence of a hydrocarbon in the exhaustreductant. A selective reduction catalyst is included in the system andconfigured to treat an exhaust gas flowing through the selectivecatalyst reduction system. In some embodiments, the exhaust reductantincludes a diesel exhaust fluid. In some embodiments, the hydrocarbondetection device includes a hydrophobic paper. In one embodiment, thehydrocarbon detection device is disposed in the filter.

In another set of embodiments, a filter for use in an aftertreatmentsystem includes a housing defining an internal volume is provided. Afilter element is disposed inside the housing and is configured tofilter particulate from an exhaust reductant. A hydrocarbon detectiondevice is disposed inside the housing and is configured to indicate thepresence of a hydrocarbon in the exhaust reductant. In some embodiments,the hydrocarbon detection device includes a hydrophobic paper. In someembodiments, the hydrocarbon detection device changes color when exposedto a hydrocarbon present in the exhaust reductant.

In yet another set of embodiments, a method for detecting the presenceof hydrocarbons in an exhaust reductant includes flowing an exhaustreductant through an exhaust reductant filter. The exhaust reductantfilter includes a housing defining an internal volume. A filter elementis disposed inside the housing and is configured to filter particulatefrom the exhaust reductant passing through the filter element. Ahydrocarbon detection device is disposed in the internal volume and isconfigured to indicate the presence of a hydrocarbon in the exhaustreductant. A change in color of the hydrocarbon detection device isobserved. The change in color represents the presence of the hydrocarbonin the exhaust reductant. The method further includes changing thefilter in response to a change in color of the hydrocarbon detectiondevice.

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, allcombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing and other features of the present disclosure will becomemore fully apparent from the following description and appended claims,taken in conjunction with the accompanying drawings. Understanding thatthese drawings depict only several implementations in accordance withthe disclosure and are, therefore, not to be considered limiting of itsscope, the disclosure will be described with additional specificity anddetail through use of the accompanying drawings.

FIG. 1 is a schematic block diagram of an aftertreatment system thatincludes a hydrocarbon detection device, according to an embodiment.

FIG. 2A is side view of an exhaust reductant filter that includes ahydrocarbon detection device disposed on an inner surface of a sidewallof the filter, according to an embodiment; and FIG. 2B shows a change incolor experience in the hydrocarbon detection device of FIG. 2A in thepresence of an exhaust redutcant that is contaminated with hydrocarbons.

FIG. 3 is a schematic flow diagram of a method for detecting thepresence of hydrocarbons in an exhaust reductant using a hydrocarbondetection device, according to an embodiment.

FIG. 4A shows a hydrocarbon detection device that includes a hydrophobicpaper that is exposed to an uncontaminated diesel exhaust fluid; andFIG. 4B shows the hydrocarbon detection device of FIG. 4A experiencing achange in color after brief exposure to a diesel exhaust fluidcontaminated with diesel fuel.

Reference is made to the accompanying drawings throughout the followingdetailed description. In the drawings, similar symbols typicallyidentify similar components, unless context dictates otherwise. Theillustrative implementations described in the detailed description,drawings, and claims are not meant to be limiting. Other implementationsmay be utilized, and other changes may be made, without departing fromthe spirit or scope of the subject matter presented here. It will bereadily understood that the aspects of the present disclosure, asgenerally described herein, and illustrated in the figures, can bearranged, substituted, combined, and designed in a wide variety ofdifferent configurations, all of which are explicitly contemplated andmade part of this disclosure.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

Embodiments described herein relate generally to exhaust aftertreatmentsystems for use with IC engines, and in particular to exhaustaftertreatment systems that include an exhaust reductant filter with ahydrocarbon detection device. Embodiments described herein may provideseveral advantages over conventional aftertreatment systems including,for example: (1) visual diagnosis of hydrocarbon contamination inexhaust reductants (e.g., diesel exhaust fluid) by observing a change incolor of the hydrocarbon detection device; (2) ability to detect verylow concentrations of the hydrocarbon in the exhaust reductant; (3) easyadaptability to conventional aftertreatment systems without anysignificant changes to the conventional aftertreatment systems; and (4)providing confirmation whether any damage to an aftertreatment system isdue to hydrocarbons in the exhaust reductant which is attributable touser error and not covered under warranty, thereby reducing erroneouswarranty claims.

FIG. 1 shows an aftertreatment system 100 which can be used for treatingexhaust gases (e.g., diesel exhaust gases) from an IC engine (e.g., adiesel engine), according to an embodiment. The aftertreatment system100 includes an exhaust reductant tank 110 a filter 130, a hydrocarbondetection device 140, and a SCR system 150. The aftertreatment system100 can be used with any IC engines, for example, diesel engines (e.g.,automotive diesel engines, marine engines, industrial power generationdiesel engines, etc.).

The exhaust reductant tank 110 is configured to store an exhaustreductant and is fluidically coupled to the filter 130. In someembodiments, the exhaust reductant tank 110 can include a diesel exhaustreductant tank and the exhaust reductant can be a diesel exhaust fluid.The diesel exhaust fluid can include, urea, an aqueous solution of urea,or any other fluid that includes ammonia, by products, or any otherdiesel exhaust fluid as is known in the arts (e.g., the diesel exhaustfluid marketed under the name ADBLUE®).

In some embodiments, the aftertreatment system 100 can also include anexhaust reductant pump (not shown). In such embodiments, the exhaustreductant pump can be fluidically coupled to the SCR system 150. Theexhaust reductant pump can be configured to pump the exhaust reductantfrom the exhaust reductant tank 110 to the SCR system 150 through thefilter 130. The exhaust reductant pump can include any suitable pump,for example, a diaphragm pump, a rotary pump, a positive displacementpump, a vacuum pump, or a combination thereof. In some embodiments, theoperation of the exhaust reductant pump can be controlled by a controlsystem (e.g., an electronic control system) to communicate a known orotherwise metered amount of the exhaust reductant into the SCR system150.

The filter 130 is configured to filter any particulate from the exhaustreductant, for example, dust, organic particles, crystals (e.g., ureacrystals), or any other solid particulates present in the exhaustreductant from entering the SCR system 150. The filter 130 can include ahousing made of a strong and rigid material such as, for example, highdensity polypropylene (HDPP) which can define an internal volume tohouse a filter element. Any suitable filter element can be used such as,for example, a cotton filter element, an acrylonitrile butadiene styrene(ABS) filter element, any other suitable filter element or a combinationthereof. The filter element can have any suitable pore size, forexample, about 10 microns, about 5 microns, or about 1 micron.

The hydrocarbon detection device 140 is configured to indicate thepresence of a hydrocarbon in the exhaust reductant. In some embodiments,the hydrocarbon detection device 140 can include a hydrophobic paper(e.g., filter paper). The hydrophobic paper can include a conventionalpaper (e.g., cellulosic paper) coated with a hydrophobic coating suchas, for example, wax, styrene maleic anhydride copolymers, siloxane,GREENCOAT®, any other suitable coating, or a combination thereof. Insome embodiments, the hydrocarbon detection device 140 can be formedfrom nylon, acrylonitrile butadiene styrene (abs), polycarbonate,cellulose, and/or polymethyl methacrylate.

The hydrocarbon detection device 140 can be configured to change colorwhen exposed to a hydrocarbon, for example, diesel fuel, injector fluid,or oil present in the exhaust reductant (e.g., a diesel exhaust fluid).For example, the hydrocarbon detection device 140 can includehydrophobic paper which can include hydrophobic non-polar groups on itssurface that repel aqueous solutions which are free of any hydrocarbons.For example, the exhaust reductant can be a diesel exhaust fluid whichis generally an aqueous solution of urea. The hydrophobic paper willthus repel uncontaminated diesel exhaust fluid, and the diesel exhaustfluid will therefore, neither wet nor moisten the hydrophobic paper.However, if the diesel exhaust fluid is contaminated with hydrocarbons(e.g., diesel fuel), the hydrocarbons will be attracted to thehydrophobic non-polar groups of the hydrophobic paper (e.g., disposed ona surface of the hydrophobic paper). The hydrocarbons can then getabsorbed in the hydrophobic paper, form a film on the surface ofhydrophobic paper, or otherwise wet the hydrophobic paper, urging thehydrophobic paper to change color. The change in color thus indicatesthat the diesel exhaust fluid is contaminated with hydrocarbons.

In some embodiments, the hydrocarbon detection device 140 can bedisposed in the filter 130. For example, the hydrocarbon detectiondevice 140 can be disposed on an inner surface of a sidewall of thefilter 130. Expanding further, the hydrocarbon detection device 140 caninclude a strip of a hydrophobic paper disposed on the inner surface ofthe sidewall of the filter 130. In such embodiments, the sidewall of thefilter 130 can be formed from a transparent or translucent materialwhich can allow observation of the strip of the hydrophobic paperthrough the sidewall of the filter. Any change in color of thehydrophobic paper can thus be attributed to the presence of one or morehydrocarbons in the exhaust reductant, as described herein.

In some embodiments, the hydrocarbon detection device 140 can beincluded in a filter element of the filter 130. For example, thehydrocarbon detection device 140 (e.g., hydrophobic paper) can becomminuted into particulates or powder, and packed in with the filterelement into the filter 130. In such embodiments, the exhaust reductantcan contact the hydrocarbon detection device 140 as it flows through thefilter element of the filter 130. If any hydrocarbon contaminants arepresent in the exhaust reductant, the hydrocarbon detection device 140included in the filter element can change color, which can appear as thefilter element changing color. This can serve to indicate that theexhaust reductant is contaminated with hydrocarbons.

In some embodiments, the hydrocarbon detection device 140 can bedisposed in the exhaust reductant tank 110. For example, the hydrocarbondetection device 140 can include a strip of hydrophobic paper disposedon an inner surface of a sidewall of the exhaust reductant tank 110. Insuch embodiments, the sidewall of the exhaust reductant tank 110 can beformed from a completely or substantially transparent or translucentmaterial to allow viewing of the hydrocarbon detection device 140through a sidewall of exhaust reductant tank 110.

In some embodiments, the hydrocarbon detection device 140 can bedisposed in both, the filter 130 and the exhaust reductant tank 110. Insome embodiments, one or more sidewalls of the filter 130 and/or theexhaust reductant tank 110 can be formed from a hydrophobic materialsuch that the sidewall of the filter 130 and/or the exhaust reductanttank 110 serves as the hydrocarbon detection device 140.

The hydrocarbon detection device 140 described herein can be configuredto detect very low concentrations of hydrocarbon contaminants present inthe exhaust reductant (e.g., a diesel exhaust fluid). In someembodiments, the hydrocarbon detection device 140 can be configured todetect the presence of hydrocarbons in the exhaust reductant at aconcentration of less than about 0.1% by weight. For example, thehydrocarbon detection device 140 can be configured to detect thepresence of the hydrocarbon in the exhaust reductant at a concentrationof less than about 1% by weight, for example, about 0.9%, 0.8%, 0.7%,0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.05%, or about 0.025% by weight,inclusive of all ranges and values therebetween.

The SCR system 150 is configured to treat an exhaust gas (e.g., a dieselexhaust gas) flowing through the SCR system 150. The SCR system 150 caninclude an injection port configured to communicate the exhaustreductant received from the exhaust reductant tank 110 via the filter130 (e.g., pumped using the exhaust reductant pump), into one or morechambers included in the SCR system 150. The exhaust reductant reactswith the exhaust gas to at least partially reduce one or more componentsof the gas (e.g., SOx and NOx), or facilitate reduction of the one ormore components in the presence of one or more catalysts.

The SCR system 150 includes one or more catalysts formulated toselectively reduce the exhaust gas. Any suitable catalyst can be usedsuch as, for example, platinum, palladium, rhodium, cerium, iron,manganese, copper, vanadium based catalyst, any other suitable catalyst,or a combination thereof. The catalyst can be disposed on a suitablesubstrate such as, for example, a ceramic (e.g., cordierite) or metallic(e.g., kanthal) monolith core which can, for example, define a honeycombstructure. A washcoat can also be used as a carrier material for thecatalysts. Such washcoat materials can include, for example, aluminumoxide, titanium dioxide, silicon dioxide, any other suitable washcoatmaterial, or a combination thereof. The exhaust gas (e.g., dieselexhaust gas) can flow over and about the catalyst such that any SOx orNOx gases included in the exhaust gas are further reduced to yield anexhaust gas which is substantially free of carbon monoxide, SOx and NOxgases.

In some embodiments, a hydrocarbon detection device can be disposedinside a filter included in an aftertreatment system. For example, FIGS.2A and 2B are side views of a filter 230 that includes a hydrocarbondetection device 240 disposed inside the filter 230. The filter 230 canbe included in any aftertreatment system, for example, theaftertreatment system 100 or any other aftertreatment system configuredto treat exhaust gases (e.g., diesel exhaust gases).

The filter 230 is configured to receive an exhaust reductant (e.g., adiesel exhaust fluid) from an exhaust reductant tank included in theaftertreatment system and to filter any particulates (e.g., dust,organic particles, crystals (e.g., urea crystals), etc.) from theexhaust reductant before it is communicated to an SCR system included inthe aftertreatment system. The filter 230 includes a housing 232 thatdefines an internal volume. A filter element 234 is disposed in theinternal volume defined by the housing 232, and is configured to filterparticulate from the exhaust reductant. For example, the filter element234 can be disposed in the internal volume such that the exhaustreductant can flow through the filter element 234 but particulates aretrapped within the filter element 234. The filter element 234 caninclude any suitable filter element capable of filtering particulatefrom the exhaust reductant before the exhaust reductant is communicatedto the SCR system. The filter element 234 can be formed from anysuitable material such as, for example, cotton, acrylonitrile butadienestyrene (ABS), any other suitable material or a combination thereof.Moreover, the filter element 234 can have any suitable pore size, forexample, about 10 microns, about 5 microns, or about 1 micron.

The hydrocarbon detection device 240 is configured to indicate thepresence of a hydrocarbon in the exhaust reductant. For example, thehydrocarbon detection device 240 can be configured to change color whenexposed to a hydrocarbon present in the exhaust reductant. In someembodiments, the hydrocarbon detection device 240 can include a strip ofhydrophobic paper such as, for example, filter paper, cellulosic papercoated with a hydrophobic coating (e.g., wax, styrene maleic anhydridecopolymers, siloxane, GREENCOAT®, any other suitable coating, or acombination thereof), or any other suitable hydrophobic paper. In someembodiments, the hydrocarbon detection device can be formed from nylon,acrylonitrile butadiene styrene (abs), polycarbonate, cellulose, and/orpolymethyl methacrylate. The hydrocarbon detection device 240 can bedisposed on an inner surface of a sidewall of the filter 230 such thatan exhaust reductant flowing through the filter can contact thehydrocarbon detection device 240. The sidewall of the filter 230 can betransparent or translucent such that the hydrocarbon detection device240 can be visually observed through the sidewall of the filter 230.

In a first instance shown in FIG. 2A an uncontaminated exhaust reductant(e.g., urea diesel exhaust fluid) flows through the filter 230. Theuncontaminated exhaust reductant does not wet or otherwise moisten thehydrocarbon detection device 240 such that the hydrocarbon detectiondevice 240 does not change color. In a second instance shown in FIG. 2B,an exhaust reductant contaminated with hydrocarbons (e.g., diesel fuel,injector fluid, and/or oil) flows through the filter 230. In suchinstances, the hydrocarbons present in the exhaust reductant can wet,cling, stick, or otherwise form a film on the hydrocarbon detectiondevice 240 urging the hydrocarbon detection device 240 to change color.For example, in the first instance, the hydrocarbon detection device 240can have a light color, and in the second instance, the hydrocarbondetection device 240 can have a dark color. The change in color can bevisually observed through the sidewall of the filter 230 and indicatethat the exhaust reductant is contaminated with one or morehydrocarbons.

While shown in FIGS. 2A and 2B as disposed on a sidewall of the filter230, in some embodiments, the hydrocarbon detection device 240 canincorporated into the filter element 234 of the filter 230, as describedherein with respect to the hydrocarbon detection device 140 included inthe system 100. In such embodiments, the hydrocarbon detection device240 incorporated into the filter element 234 will change color in thepresence of hydrocarbons which can appear as a change in color of theentire filter element 232. Furthermore, the hydrocarbon detection device240 can be configured to detect the presence of hydrocarbon in theexhaust reductant (e.g., diesel exhaust fluid) at very lowconcentrations. In some embodiments, the hydrocarbon detection device240 can be configured to detect the presence of the hydrocarbon in theexhaust reductant at a concentration of less than about 1% by weight,for example, about 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%,0.05%, or about 0.025% by weight, inclusive of all ranges and valuestherebetween.

FIG. 3 is a schematic flow diagram of an exemplary method 300 fordetecting hydrocarbons present in an exhaust reductant (e.g., a dieselexhaust fluid as described herein) flowing through an aftertreatmentsystem using a hydrocarbon detection device. The method 300 can be usedwith any aftertreatment system, for example, the aftertreatment system100 and can be incorporated into any aftertreatment process or method.

The method 300 includes flowing an exhaust reductant through an exhaustreductant filter, at 302. The exhaust reductant can include dieselexhaust fluid (e.g., an aqueous urea solution) or any other suitableexhaust reductant as described herein. The exhaust reductant filterincludes a housing defining an internal volume. A filter element isdisposed in the internal volume and is configured to filter particulatefrom an exhaust reductant passing through the filter element. The filterelement can include any suitable filter element as described withrespect to the filter 130, 230, or any other filter described herein.

A hydrocarbon detection device is disposed in the internal volume of theexhaust reductant filter. The hydrocarbon detection device is configuredto indicate the presence of a hydrocarbon in the exhaust reductant. Thehydrocarbon detection device can be substantially similar to thehydrocarbon detection device 140, 240, or any other hydrocarbondetection device described herein. In some embodiments, the hydrocarbondetection device can include a hydrophobic paper (e.g., as describedwith respect to the hydrophobic detection device 140, or 240). In someembodiments, the hydrocarbon detection device can be disposed on aninner surface of a sidewall of the exhaust reductant filter. In suchembodiments, the sidewall of the exhaust reductant filter can betransparent or translucent to allow viewing of the hydrocarbon detectiondevice through the sidewall.

The method 300 further includes observing a potential change in color ofthe hydrocarbon detection device, at 304. The change in color representsthat a hydrocarbon is present in the exhaust reductant. It is thendetermined if the hydrocarbon detection device changed color, at 306. Ifthe hydrocarbon detection device did not change color, no action istaken and the method 300 returns to operation 302. If on the other hand,the hydrocarbon detection device changed color, the exhaust reductantfilter is changed at 308.

The method 300 can enable detection of hydrocarbons in diesel exhaustfluid at very low concentrations. For example, the hydrocarbon detectiondevice can be configured to detect the presence of the hydrocarbon inthe diesel exhaust fluid at a concentration of less than about 1% byweight, for example, about 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%,0.2%, 0.1%, 0.05%, or about 0.025% by weight, inclusive of all rangesand values therebetween.

Hydrocarbon Detection Device Including a Hydrophobic Paper

FIG. 4A shows a hydrocarbon detection device that includes a strip ofhydrophobic paper. The hydrophobic paper included cellulose paper with awax coating. The hydrophobic paper was light blue in color in its drystate. Diesel exhaust fluid that includes about 33% by volume urea inwater and was free of hydrocarbons was poured on the hydrophobic paper.The diesel exhaust fluid did not wet the hydrophobic paper and no changein color of the hydrophobic paper was observed as shown in FIG. 4A. Thesame diesel exhaust fluid, but now contaminated with about 0.05% byweight of diesel fuel, was then poured on the hydrophobic paper. Thehydrophobic paper changed color and turned dark blue on contact with thecontaminated diesel exhaust fluid. This clearly shows that thehydrophobic paper can be used as a detection device for detectinghydrocarbons in diesel exhaust fluid.

As used herein, the terms “about” and “approximately” generally meanplus or minus 10% of the stated value. For example, about 0.5 wouldinclude 0.45 and 0.55, about 10 would include 9 to 11, about 1000 wouldinclude 900 to 1100.

As used herein, the singular forms “a”, “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, the term “a member” is intended to mean a single member or acombination of members, “a material” is intended to mean one or morematerials, or a combination thereof.

It should be noted that the term “exemplary” as used herein to describevarious embodiments is intended to indicate that such embodiments arepossible examples, representations, and/or illustrations of possibleembodiments (and such term is not intended to connote that suchembodiments are necessarily extraordinary or superlative examples).

The terms “coupled,” “connected,” and the like as used herein mean thejoining of two members directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent) or moveable (e.g., removableor releasable). Such joining may be achieved with the two members or thetwo members and any additional intermediate members being integrallyformed as a single unitary body with one another or with the two membersor the two members and any additional intermediate members beingattached to one another.

It is important to note that the construction and arrangement of thevarious exemplary embodiments are illustrative only. Although only a fewembodiments have been described in detail in this disclosure, thoseskilled in the art who review this disclosure will readily appreciatethat many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Othersubstitutions, modifications, changes and omissions may also be made inthe design, operating conditions and arrangement of the variousexemplary embodiments without departing from the scope of the presentinvention.

What is claimed is:
 1. An aftertreatment system, comprising: an exhaustreductant tank configured to store an exhaust reductant; a filter; ahydrocarbon detection device coupled to at least one of the exhaustreductant tank or the filter, the hydrocarbon detection deviceconfigured to indicate the presence of a hydrocarbon in the exhaustreductant, the hydrocarbon detection device comprises one of (1) ahydrophobic paper and (2) at least one of nylon, acrylonitrile butadienestyrene, polycarbonate, cellulose, a cellulose paper coated with ahydrophobic coating, or polymethyl methacrylate; and a selectivecatalytic reduction system configured to treat an exhaust gas flowingthrough the selective catalytic reduction system.
 2. The aftertreatmentsystem of claim 1, wherein the exhaust reductant tank is a dieselexhaust fluid tank, and wherein the exhaust reductant is a dieselexhaust fluid.
 3. The aftertreatment system of claim 1, wherein thehydrocarbon detection device changes color when exposed to thehydrocarbon present in the exhaust reductant.
 4. The aftertreatmentsystem of claim 1, wherein the hydrocarbon includes at least one of adiesel fuel, an injector cleaner, or an oil.
 5. The aftertreatmentsystem of claim 4, wherein the hydrocarbon detection device is disposedon an inner surface of a sidewall of the filter.
 6. The aftertreatmentsystem of claim 5, wherein the filter is configured to allow viewing ofthe hydrocarbon detection device through a sidewall of the filter. 7.The aftertreatment system of claim 1, wherein the hydrocarbon detectiondevice is disposed in the filter.
 8. The aftertreatment system of claim1, wherein the hydrocarbon detection device is disposed in the exhaustreductant tank.
 9. The aftertreatment system of claim 1, furthercomprising an exhaust reductant pump configured to pump the exhaustreductant from the exhaust reductant tank to the selective catalyticreduction system through the filter.
 10. The aftertreatment system ofclaim 1, wherein the hydrocarbon detection device is configured todetect the presence of the hydrocarbon in the exhaust reductant at aconcentration of less than 1% by weight.
 11. The aftertreatment systemof claim 1, wherein the hydrocarbon detection device is configured todetect the presence of the hydrocarbon in the exhaust reductant at aconcentration of less than 0.1% by weight.
 12. A filter for use in anaftertreatment system, the filter comprising: a housing defining aninternal volume; a filter element disposed in the internal volume, thefilter element configured to filter particulate from an exhaustreductant passing through the filter element; and a hydrocarbondetection device disposed in the internal volume, the hydrocarbondetection device comprises one of (1) a hydrophobic paper and (2) atleast one of nylon, acrylonitrile butadiene styrene, polycarbonate,cellulose, a cellulose paper coated with a hydrophobic coating, orpolymethyl methacrylate, the hydrocarbon detection device configured toindicate the presence of a hydrocarbon in the exhaust reductant.
 13. Thefilter of claim 12, wherein the hydrocarbon detection device changescolor when exposed to a hydrocarbon present in the exhaust reductant.14. The filter of claim 12, wherein the hydrocarbon detection device isdisposed on an inner surface of a sidewall of the filter.
 15. The filterof claim 14, wherein the filter is configured to allow viewing of thehydrocarbon detection device through a sidewall of the filter.
 16. Thefilter of claim 12, wherein the hydrocarbon detection device is includedin the filter element of the filter.
 17. The filter of claim 12, whereinthe hydrocarbon detection device is configured to detect the presence ofthe hydrocarbon in the exhaust reductant at a concentration of less than1% by weight.
 18. A method for detecting the presence of hydrocarbons inan exhaust reductant flowing through an aftertreatment system, themethod comprising: flowing an exhaust reductant through an exhaustreductant filter, the exhaust reductant filter including: a housingdefining an internal volume; a filter element disposed in the internalvolume, the filter element configured to filter particulate from anexhaust reductant passing through the filter element; and a hydrocarbondetection device disposed in the internal volume, the hydrocarbondetection device configured to indicate the presence of a hydrocarbon inthe exhaust reductant; observing a change in color of the hydrocarbondetection device, the change in color representing the presence of thehydrocarbon in the exhaust reductant; and in response to observing thechange in color, changing the exhaust reductant filter.
 19. The methodof claim 18, wherein the hydrocarbon detection device comprises ahydrophobic paper.
 20. The method of claim 18, wherein the hydrocarbondetection device is disposed on an inner surface of a sidewall of theexhaust reductant filter.
 21. The method of claim 18, wherein thehydrocarbon detection device is configured to detect the presence of thehydrocarbon in the exhaust reductant at a concentration of less than 1%by weight.
 22. An aftertreatment system, comprising: an exhaustreductant tank configured to store an exhaust reductant; a filter; ahydrocarbon detection device configured to indicate the presence of ahydrocarbon in the exhaust reductant, the hydrocarbon detection devicecomprises one of (1) a hydrophobic paper and (2) at least one of nylon,acrylonitrile butadiene styrene, polycarbonate, cellulose, a cellulosepaper coated with a hydrophobic coating, or polymethyl methacrylate; anda selective catalytic reduction system configured to treat an exhaustgas flowing through the selective catalytic reduction system; whereinthe hydrocarbon detection device is disposed in the filter.
 23. Anaftertreatment system, comprising: an exhaust reductant tank configuredto store an exhaust reductant; a filter; a hydrocarbon detection deviceconfigured to indicate the presence of a hydrocarbon in the exhaustreductant, the hydrocarbon detection device comprises one of (1) ahydrophobic paper and (2) at least one of nylon, acrylonitrile butadienestyrene, polycarbonate, cellulose, a cellulose paper coated with ahydrophobic coating, or polymethyl methacrylate; and a selectivecatalytic reduction system configured to treat an exhaust gas flowingthrough the selective catalytic reduction system; wherein thehydrocarbon includes at least one of a diesel fuel, an injector cleaner,or an oil; wherein the hydrocarbon detection device is disposed on aninner surface of a sidewall of the filter; and wherein the filter isconfigured to allow viewing of the hydrocarbon detection device througha sidewall of the filter.
 24. A filter for use in an aftertreatmentsystem, the filter comprising: a housing defining an internal volume; afilter element disposed in the internal volume, the filter elementconfigured to filter particulate from an exhaust reductant passingthrough the filter element; and a hydrocarbon detection device disposedin the internal volume, the hydrocarbon detection device comprises oneof (1) a hydrophobic paper and (2) at least one of nylon, acrylonitrilebutadiene styrene, polycarbonate, cellulose, a cellulose paper coatedwith a hydrophobic coating, or polymethyl methacrylate, the hydrocarbondetection device configured to indicate the presence of a hydrocarbon inthe exhaust reductant; wherein the hydrocarbon detection device isincluded in the filter element of the filter.
 25. The filter of claim24, wherein the filter is configured to allow viewing of the hydrocarbondetection device through a sidewall of the filter.